docs: fix typos in comments, docstrings and an error message

[Avicennasis]

Description

Fixes 10 spelling and grammar mistakes in Python comments, docstrings and one user-facing API error message. Contributing guide asks that PRs have "no spelling mistakes", so this cleans up some existing ones.

No behaviour changes, no identifiers renamed, no tests affected.

Scope note: accross -> across in run_metric.py was not in the original list I was working from - I added it because it sits two words after tahty on the same line, and correcting one while walking past the other would have looked arbitrary. It is the only occurrence of accross in the repository. Everything else below was identified up front.

web/api/maestro_api/db/repo/run_metric.py

• Stores reusable queries over metrics tahty can be reused accross the project -> that can be reused across the project (two misspellings on the one line)
• Group metrics by passed amout of seconds -> amount of seconds
• # Counts should be devided by interval -> divided by interval

web/api/maestro_api/services/auth/authorization.py

• algorithms (list): Argorythms used for decoding -> Algorithms used for decoding
• {"description": "The token as expired"} -> "The token has expired" (this string is returned to API clients on an expired JWT; it appears nowhere else in the repo, so no test assertions needed updating)

web/api/maestro_api/controllers/run.py

• "Get Single Run run by ID" -> "Get Single Run by ID" (duplicated word; this docstring is the endpoint's description)
• Run itself is fully independant instance -> independent instance

agent/maestro_agent/services/jmeter/properties.py

• Build dict of properties based on overrideds priorities -> override priorities
• # The value can be overriden by using environment variable -> overridden

agent/maestro_agent/services/docker.py

• # We need to configure SHH client properly -> SSH client

Dependencies

None.

Checklist

• The commit message follows our guidelines (conventional commits: docs:)
• Tests for the respective changes have been added - not applicable, comment/docstring text only; the one changed runtime string is not asserted on anywhere in the repo
• The labels and/or milestones were added - happy to add whatever you prefer